Hi All,

My car has loads of black smoke when accelerating. I would like to check with you if my turbo is dying. Fiat Stilo MW 1.9 JTD 8V 115HP October 2005 with 300,000km (192,000 miles)

Things checked/done till know.
-EGR Blocked
-Airflow Sensor cleaned
-MAP cleaned (was really dirty and oily - see pic attached)
-New oil and filters
-Prayed to Fiat Gods

Anyone other ideas before I sell my kids to buy a new turbo?

br/


Dawid Kowalczys

Mine was smokey too and was suffering from poor pick-up .. especially when I accelerated but it's all smoke free and tramps along well, now.

I did:

1) Check the oil level. Mine was about 3mm too high (over MAX on the dipstick) and oil was getting pushed into the inlet manifold, via the crankcase breather. Eventually it was getting sucked back into the combustion chamber.

2) Blanked off the EGR valve after cleaning it to make sure it moved freely.

3) Replaced the MAP sensor for the price of a new one... (it was full of oil and sh*t like yours).

4) Replaced the turbo boost valve (under the battery box)

5) Removed all the airbox/pipes and cleaned them out. They had a lot of oil in them.

6) Cleaned the MAF sensor (electric contact cleaner spray).


Of these, blanking the EGR made the biggest difference, I have to say.

The turbo boost valve was probably un-necessary but I was on a mission.. I would buy a new MAP sensor rather than hope the old one is clean and working.

The rest was just cleaning and furtling, so easy to do.


Ralf S.

Thx Ralf S.

I will try to replace the MAP sensor to see it that will help.

Is there a way to check a turbo without removin 50% of the engine? MultiEcuScan?

Black smoke on a diesel essentially means you're running rich; i.e. there is too much fuel compared to the amount of air being burnt.


Check your turbo hoses for leaks - check thoroughly. You might find if it is leaking you'll see black, oily, sooty deposits where it's been blowing out. The oil vapour recirculation system tends to mean you get oil condensing on the side of your charge air pipes. That is why you see your MAP sensor is dirty.


When the EGR opens it lets exhaust soot in, this mixes with the oil and forms a thick slime. At least you have the EGR blocked, which is good.


Remember a pin hole in the pipe at atmospheric pressure, once boost is generated at like 1 bar, that pin hole will turn into something the size of a 1p / 1 cent coin.


A decent sized boost leak you will hear an audible hiss / rushing of air when you are on hard throttle. You should hear nothing but a faint whilst of the turbo.


A failing turbo will start to howl or whilst loudly, your oil use will also increase. you can check the bearings on the turbo (when engine is old - otherwise you will burn yourself) by taking the boost pipe off the turbo and checking for play in the turbo shaft. You should have a little bit of play in the push/pull in/out direction, that is fine maybe 1 or 2mm, but if you've got any movement in the up/down direction then that indicates bearing wear and possibly needs action.


After that the only elements in the circuit controlling the amount of air are the MAP, MAF and VNT solenoid.


MAF is a good potential. They're a heated element so they do wear out over time. Make sure you use genuine BOSCH replacement - you can get cheap ones but they do not work and the quality of them is very poor.


MAP sensor, as long as it's clean should work fine. No real way of testing these though so you have to trust you instinct. Not overly expensive to replace though.


VNT solenoid, if failing tends to manifest itself in a lack of power and or overboost issues.


You can check via diag software the boost pressure vs desired boost pressure. This will give you some indication that your not reading boost correctly (i.e. MAP sensor) or you're not making desired boost (VNT solenoid).




My initial favourite for you - boost leak or MAF.

dear Artermis,

thank you for your replay and the time you spent on it. information included will help me a lot. in couple of months i will be visiting my fammily and there is a place where i can work on my car. i will follow you suggestions and make a haw to with pictures, hopefully thus will help other diesel users as well

br/

Dawid